The relative contribution of physical processes leading the May 2024 heat wave in Cuba using a novel temperature anomaly analysis

Several weather stations reported record-breaking air maximum temperatures in May 2024 in Cuba. While the general mechanisms driving heat waves (HWs) in this region are known, the relative contribution of adiabatic, diabatic, and advective processes in causing the near-surface temperature anomalies (T′) remains unclear. Addressing this knowledge gap, this study examines the driver mechanisms of these abnormally high temperatures and quantifies the contributions of these physical processes. Unlike previous studies that often focused on individual processes, we applied a novel T′ decomposition and source analysis approach along air parcel backward trajectories to achieve this goal. Results show that most of the Cuban territory was under HW conditions, particularly the central and western regions, which reported T′ reaching 3–4 °C (considering the 1991–2020 average). The T′ decomposition framework revealed the local-origin sources for T'. Beneath clear skies, subsidence and increased insolation related to high pressures on the surface and high geopotential centres in the lower and middle atmosphere favoured adiabatic warming as the primary mechanism for rising temperatures, followed by advective processes with a weak contribution. Meanwhile, diabatic processes negatively contributed. Overall, this study enhances our understanding of the drivers' mechanisms of HWs in Cuba by quantitatively corroborating the importance of local warming processes and providing a guide for examining such extremes in the context of global warming.